Characterization of thermophilic streptococci isolated from rustic white cheese

Al-Mariri, Ayman; younes, Ahed Abou; Sharabi, Nagim-Eldin

doi:10.2323/jgam.59.097

Cited by 3 publications

(2 citation statements)

References 30 publications

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“…11,22 On one hand some vancomycin-resistant strains VRE cause healthcare associated infections; on the other hand, other strains are used as probiotics in both humans and animals 23,24 and are among the dominant members of the microflora of many cheeses. 25,26 In the research 22 E. faecium survived heating at 50℃ after 2 hours, but showed no growth at 52℃. According to the systematic review conducted by Kramer and co-authors, 27 Enterococcus spp., including VRE, can survive between 5 days and 4 months on dry surfaces.…”

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confidence: 90%

Survival of Enterococcus faecium, Staphylococcus aureus and Pseudomonas aeruginosa on cotton

Fijan

Pahor

Turk

2016

Textile Research Journal

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The aim of this study was to evaluate the survival of three challenge bacteria stored at 25℃, 5℃, and 50℃ up to 21 days on 100% cotton textile swatches. The survival of each chosen challenge bacteria was determined by the classical phenotype colony counting method through growth on selective media, and the molecular method of detecting Staphylococcus aureus-, Enterococcus faecium-, and Pseudomonas aeruginosa-specific DNA. E. faecium proved to be the most persistent chosen challenge bacteria at all three chosen storage temperatures. Both E. faecium and S. aureus survived on textile swatches up to 21 days at 25℃ at the highest inoculum. E. faecium and P. aeruginosa persisted at 50℃ only up to 9 and 3 days, respectively. All challenge bacteria survived on textile swatches at 5℃ ( E. faecium 12 days, P. aeruginosa and S. aureus less than 6 days). The results of survival at lower initial inoculum were lower and less dependent on temperature. Dehydration phenomena or fluctuation in relative humidity in the refrigerator at 5℃ possibly explains lower survival than at room temperature. Positive results for the detection of E. faecium- and P. aeruginosa-specific DNA were found for some samples with negative results for classical phenotype counting methods, perhaps owing to the fact that the bacterial cells, due to adverse environmental conditions, reached a viable, but noncultivable (VBNC) state, or that the extracellular DNA fragments persisted on the textiles. Survival of the challenge bacteria for more than 3 days regardless of temperature proves that hospital textiles as an inanimate surface should not be neglected as one of the possible vectors for transmission of pathogens causing healthcare associated infections.

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confidence: 90%

Survival of Enterococcus faecium, Staphylococcus aureus and Pseudomonas aeruginosa on cotton

Fijan

Pahor

Turk

2016

Textile Research Journal

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“…S. thermophilus is also used as a starter culture for producing fermented milk products other than yogurt (e.g., labneh and skyr) and cheese (e.g., parmesan cheese and Swiss cheese) (Iyer et al, 2010). As a result, the isolation and characterization of S. thermophilus strains from dairy products has been widely researched (Al-Mariri et al, 2013;Delorme et al, 2017;El-Baradei et al, 2008;Mora et al, 2002). In contrast, little research has been done on the isolation of S. thermophilus from non-dairy products (Michaylova et al, 2007;Muyanja et al, 2003;Nakata et al, 2010;Umamaheswari et al, 2014).…”

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confidence: 99%

Isolation of <i>Streptococcus thermophilus</i> Strains from Plants in Japan and Their Application to Milk Fermentation

Saito

Tonouchi

Harada

et al. 2020

FSTR

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Streptococcus thermophilus is a lactic acid bacterium used along with Lactobacillus delbrueckii subsp. bulgaricus as a starter culture for yogurt production. Thus, there are many reports on the isolation and characterization of S. thermophilus from dairy products. On the other hand, literature on the isolation of S. thermophilus from plants is limited. Here, we investigate the isolation of S. thermophilus from 688 samples of twigs, leaves, stems, flowers, and berries collected from healthy trees (66 species) and grasses (40 species) found in Japan. Eight S. thermophilus strains were obtained from Acer palmatum var. matsumurae, Cornus controversa, C. officinalis, Fagus crenata, Lagerstroemia indica, Magnolia denudata, and Quercus crispula var. crispula. Then, we evaluated the characteristics of milk fermentation by using these eight strains. All eight strains fermented milk, and six of them coagulated 10 % (w/v) skim milk within 6 h at 40 ℃. Finally, we characterized susceptibility to syneresis by centrifugation. Milk fermented by the plant strains was more resistant to syneresis than milk fermented by three S. thermophilus strains isolated from commercial yogurts. We found that S. thermophilus can be isolated from some plants found in Japan, and these plants are useful sources of S. thermophilus for milk fermentation.

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Presence of Different Bacterial Species in Thermal Sources and Novelty in Their Industrial Enzyme Productions

Albayrak¹,

Genç²,

Özkan³

et al. 2019

J Pure Appl Microbiol

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In this study, one hundred and thirty isolates were isolated from water and sludge samples taken from hot springs located in different regions of Turkey. Among them, eleven isolates were chosen according to conventional (morphological, physiological and biochemical tests) and molecular methods (rep-PCR and 16S rRNA sequencing). These bacteria were then tested for their capability to produce valuable enzymes. As a result; species belonging to Bacillus, Anoxybacillus, Aeribacillus, Enterococcus, Exiguobacterium and Paenibacillus were identified. Test strains were found to have optimum reproductive potential at pH 5.0-9.0 and 15-65°C, usually at a concentration of 1.0-10.0% (w/v) NaCl. In addition, all thermotolerant bacteria were Gram, endospore (except E. profundum), catalase and oxidase (except E. faecium and E. profundum) positive, and rod-shaped (except E. faecium). It was observed that all isolates had a 99% similarity percentage as a result of 16S rRNA sequence analysis. All of the isolates were capable of producing industrially important enzymes moreover, eight of them could produce at least two of these enzymes. Test strains had high potential of industrial enzyme production, and the enzymes from these thermo-tolerant isolates will be widely used in biotechnological processes.

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Characterization of thermophilic streptococci isolated from rustic white cheese

Cited by 3 publications

References 30 publications

Survival of Enterococcus faecium, Staphylococcus aureus and Pseudomonas aeruginosa on cotton

Survival of Enterococcus faecium, Staphylococcus aureus and Pseudomonas aeruginosa on cotton

Isolation of <i>Streptococcus thermophilus</i> Strains from Plants in Japan and Their Application to Milk Fermentation

Presence of Different Bacterial Species in Thermal Sources and Novelty in Their Industrial Enzyme Productions

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